Athlete hid shine, upset he’d become very important (3,3,9)
I believe the answer is:
hit the headlines
'he'd become very important' is the definition.
I know nothing about this answer so I cannot judge whether it can be defined by this definition.
'athlete hid shine upset' is the wordplay.
'upset' is an anagram indicator.
'athlete'+'hid'+'shine'='athletehidshine'
'athletehidshine' with letters rearranged gives 'HIT THE HEADLINES'.
Can you help me to learn more?
(Other definitions for hit the headlines that I've seen before include "advertise one's activities?" , "get prominent media attention" , "were featured prominently" , "made the papers" , "Do something newsworthy" .)